This invention relates to endless tracks utilized on track-type vehicles. In particular, this invention relates to a resilient element and means for interposing the resilient element between adjacent track shoes which are removably affixed to links of an endless track. The resilient element serves to reduce impact velocity between adjacent shoe members during flexure of the track. Such reduction of impact velocity lessens impact shock resulting in a lower operating noise level. Further, the reduction of impact velocity tends to prevent slippage between the shoe and associated link, thus lessening shoe bolt loosening or breakage and, therefore, prolonging shoe life.
Conventional tracks utilized in track type vehicles comprise a series of links interconnected by hinge elements. Affixed to each link is a shoe having a cleat or grouser portion extending outwardly therefrom to provide traction. The construction of the track allows it to flex in one direction as it is rotated by the sprocket about the track assembly. The track may also flex in the other or opposite direction to a limited degree as, for example, when the track contacts an obstruction and is urged inwardly of the track mechanism. Such flexure in this second opposite direction is usually limited by the overlap portion of one shoe contacting the grouser portion of the adjacent shoe. Such motion is known in the art as "back-bend" to the track. Back-bend motion, although necessary for proper operation of the vehicle, causes noise and increased wear to the shoe.
Noise problems created by the endless track moving over the drive sprocket and associated idler sprocket of a tractor have been long recognized and efforts to reduce noise from this source have been relatively successful by incorporation of resilient lugs interposed between the hinge pins of the endless track to reduce impact force of the hinge pins contacting the sprocket. Relatively successful efforts to eliminate noise and wear associated with the drive sprocket has brought to the forefront the noise problem associated with contact between adjacent shoes. By increasing the base size of these midpoint resilient lugs, as taught in U.S. Pat. No. 3,887,244, relative impact velocity during back-bend between adjacent shoes can be reduced in newer type track assemblies.
Although efforts to eliminate these sources of noise between the track and the drive sprocket and between adjacent shoes has markedly reduced the ambient noise level associated with operation of newer crawler tractors; local, state and federal regulations are continually imposing new and stricter noise limitations on construction type vehicles and the like; thus, diminution of noise associated with back-bend motion in track assemblies not readily modifiable to track assemblies with resilient mid-point lugs is appropriate.